/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.dex.file;

import com.android.dx.dex.SizeOf;
import com.android.dx.rop.cst.CstString;
import com.android.dx.util.AnnotatedOutput;
import com.android.dx.util.Hex;

/**
 * Representation of a string inside a Dalvik file.
 */
public final class StringIdItem extends IndexedItem implements Comparable {

	/** {@code non-null;} the string value */
	private final CstString value;

	/** {@code null-ok;} associated string data object, if known */
	private StringDataItem data;

	/**
	 * Constructs an instance.
	 * 
	 * @param value
	 *            {@code non-null;} the string value
	 */
	public StringIdItem(CstString value) {
		if (value == null) {
			throw new NullPointerException("value == null");
		}

		this.value = value;
		this.data = null;
	}

	/** {@inheritDoc} */
	@Override
	public boolean equals(Object other) {
		if (!(other instanceof StringIdItem)) {
			return false;
		}

		StringIdItem otherString = (StringIdItem) other;
		return value.equals(otherString.value);
	}

	/** {@inheritDoc} */
	@Override
	public int hashCode() {
		return value.hashCode();
	}

	/** {@inheritDoc} */
	public int compareTo(Object other) {
		StringIdItem otherString = (StringIdItem) other;
		return value.compareTo(otherString.value);
	}

	/** {@inheritDoc} */
	@Override
	public ItemType itemType() {
		return ItemType.TYPE_STRING_ID_ITEM;
	}

	/** {@inheritDoc} */
	@Override
	public int writeSize() {
		return SizeOf.STRING_ID_ITEM;
	}

	/** {@inheritDoc} */
	@Override
	public void addContents(DexFile file) {
		if (data == null) {
			// The string data hasn't yet been added, so add it.
			MixedItemSection stringData = file.getStringData();
			data = new StringDataItem(value);
			stringData.add(data);
		}
	}

	/** {@inheritDoc} */
	@Override
	public void writeTo(DexFile file, AnnotatedOutput out) {
		int dataOff = data.getAbsoluteOffset();

		if (out.annotates()) {
			out.annotate(0, indexString() + ' ' + value.toQuoted(100));
			out.annotate(4, "  string_data_off: " + Hex.u4(dataOff));
		}

		out.writeInt(dataOff);
	}

	/**
	 * Gets the string value.
	 * 
	 * @return {@code non-null;} the value
	 */
	public CstString getValue() {
		return value;
	}

	/**
	 * Gets the associated data object for this instance, if known.
	 * 
	 * @return {@code null-ok;} the associated data object or {@code null} if
	 *         not yet known
	 */
	public StringDataItem getData() {
		return data;
	}
}
